C-8-Selective Allylation of Quinoline: A Case Study of β-Hydride vs β-Hydroxy Elimination

An unprecedented C(8)-H bond allylation of quinoline with allyl carbonate and allyl alcohol catalyzed by Cp*Co(III) using a traceless directing group via beta-oxygen and beta-hydroxy elimination is described. This site-selective allylation reaction proceeds smoothly with various functional group tolerance including quinoxaline and phenanthridine. Under the nonoxidative reaction conditions, the difference in selectivity between Rh(III) and Co(III), which proceeds through beta-hydride and beta-hydroxy elimination using allyl alcohol, is shown for the first time.